Research, Research Articles
Effect of paraquat-induced oxidative stress on gene expression and aging of the filamentous ascomycete Podospora anserina
Matthias Wiemer and Heinz D. Osiewacz
In this article, paraquat is used to experimentally induce strong cellular oxidative stress in Podospora anserina wild-type cultures of different age, finding that this treatment has profound effects on gene expression, growth and lifespan.
Heat shock protein 90 and calcineurin pathway inhibitors enhance the efficacy of triazoles against Scedosporium prolificans via induction of apoptosis
Fazal Shirazi and Dimitrios P. Kontoyiannis
This article reports for the first time that posaconazole (PCZ) or itraconazolein (ICZ) in combination with the calcineurin inhibitor tacrolimus or the Hsp90 inhibitor 17-demethoxy-17-(2-propenylamino) geldanamycin renders S. prolificans exquisitely sensitive to PCZ or ICZ via apoptosis.
At neutral pH the chronological lifespan of Hansenula polymorpha increases upon enhancing the carbon source concentrations
Adam Kawałek and Ida J. van der Klei
The data presented in this work indicate that in H. polymorpha at neutral pH the chronological lifespan invariably extends upon increasing the carbon source concentration.
Salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA
Qiuqiang Gao1, Liang-Chun Liou2, Qun Ren2, Xiaoming Bao3 and Zhaojie Zhang2
In this work, the authors report that salt stress causes cell wall damage in yeast cells lacking mitochondrial DNA (ρ0) and that this damage is related to elevated levels of SCW11 and salt stress-induced reactive oxygen species.
Protein oxidation in the intermembrane space of mitochondria is substrate-specific rather than general
Valentina Peleh1, Jan Riemer2, Andrew Dancis3 and Johannes M. Herrmann1
In this work, the authors suggest that in Saccharomyces cerevisiae, the Mia40-dependent oxidation of proteins in the intermembrane space only takes place in specific proteins and presumably relies on the presence of Mia40-binding sites.
Deletion of AIF1 but not of YCA1/MCA1 protects Saccharomyces cerevisiae and Candida albicans cells from caspofungin-induced programmed cell death
Christopher Chin1,2,#, Faith Donaghey1,#, Katherine Helming1,3,#, Morgan McCarthy1,#, Stephen Rogers1, and Nicanor Austriaco1
This work suggests that deleting AIF1 but not YCA1/MCA1 protects S. cerevisiae and Candida albicans from caspofungin-induced cell death. This is not only the first time that AIF1 has been specifically tied to cell death in Candida but also the first time that caspofungin resistance has been linked to the cell death machinery in yeast.
Reduced TORC1 signaling abolishes mitochondrial dysfunctions and shortened chronological lifespan of Isc1p-deficient cells
Vitor Teixeira1,2, Tânia C. Medeiros1, Rita Vilaça1,2, Pedro Moradas-Ferreira1,2, and Vítor Costa1,2
Overall, this article shows that the TORC1-Sch9p axis is deregulated in Isc1p-deficient Saccharomyces cerevisiae cells, contributing to mitochondrial dysfunction, enhanced oxidative stress sensitivity and premature aging of isc1Δ cells.
Early manifestations of replicative aging in the yeast Saccharomyces cerevisiae.
Maksim I. Sorokin1,3, Dmitry A. Knorre2,3, and Fedor F. Severin2,3
The data preseted herein suggest that retrograde signaling starts to malfunction in relatively young cells, leading to accumulation of heterogeneous mitochondria within one cell. The latter may further contribute to a decline in stress resistances.
Tracking autophagy during proliferation and differentiation of Trypanosoma brucei
William R. Proto1, Nathaniel G. Jones1, Graham H. Coombs2, and Jeremy C. Mottram1
This article provides insights into the function of autophagy, a cellular degradation and recycling pathway, in the protozoan parasite Trypanosoma brucei.
VDAC regulates AAC-mediated apoptosis and cytochrome c release in yeast
August 25, 2016
Mitochondrial outer membrane permeabilization is a key event in apoptosis processes leading to the release of lethal factors. In this study, we sought to determine whether Por1p functionally interacts with ADP/ATP carrier (AAC) proteins, as well as its contribution to cytochrome c release and yeast apoptosis induced by acetic acid treatment. Our data indicate that Por1p may regulate cell survival by acting as a negative regulator of AAC proteins in the apoptotic cascade.
Attenuation of polyglutamine-induced toxicity by enhancement of mitochondrial OXPHOS in yeast and fly models of aging
July 26, 2016
Defects in mitochondrial biogenesis and function are common in many neurodegenerative disorders, including Huntington’s disease (HD). We could shown that enhancement of mitochondrial biogenesis protects against neurodegeneration in HD yeast and fly models. Our results suggest that therapeutic interventions aiming at the enhancement of mitochondrial respiration and OXPHOS could reduce polyQ toxicity and delay disease onset.
Cox1 mutation abrogates need for Cox23 in cytochrome c oxidase biogenesis
June 30, 2016
Cox23 is a known conserved assembly factor for cytochrome c oxidase, although its role in cytochrome c oxidase (CcO) biogenesis remains unresolved. To gain additional insights into its role, we isolated spontaneous suppressors of the respiratory growth defect in cox23∆ yeast cells. In this report, we describe the isolation of a robust suppressor of the respiratory defect in cox23∆ cells that mapped to the mitochondrial-encoded Cox1 subunit.
Construction and evaluation of yeast expression networks by database-guided predictions
May 10, 2016
DNA-Microarrays are powerful tools to obtain expression data on the genome-wide scale. We set out to define a way to cluster microarray data according to their expressional relationship and to obtain information on the significance of this clustering approach.
Optogenetic monitoring identifies phosphatidylthreonine-regulated calcium homeostasis in Toxoplasma gondii
May 1, 2016
Toxoplasma gondii is an obligate intracellular parasite, which inflicts acute as well as chronic infections in a wide range of warm-blooded vertebrates. Using an optogenetic sensor to monitor subcellular calcium in this model intracellular pathogen we found a novel regulatory function of phosphatidylthreonine in calcium signaling.
Formaldehyde fixation is detrimental to actin cables in glucose-depleted S. cerevisiae cells
April 13, 2016
Actin filaments form cortical patches and emanating cables in fermenting cells of Saccharomyces cerevisiae. We assume that stability of actin cables reflects the metabolic status of the cell. Based on comparison of live and formaldehyde-fixed cells, our data suggest that formaldehyde affects respiration before fixation and this uneven signaling results in destabilization of actin cables in glucose-deprived cells.
Insights into dynamin-associated disorders through analysis of equivalent mutations in the yeast dynamin Vps1
March 22, 2016
The dynamins represent a superfamily of proteins that have been shown to function in a wide range of membrane fusion and fission events. An increasing number of mutations in the human classical dynamins, Dyn-1 and Dyn-2 has been reported, with diseases caused by these changes ranging from Charcot-Marie-Tooth disorder to epileptic encephalopathies. This study aimed to use the dynamin-like protein Vps1 of Saccharomyces cerevisiae as a model to gain insights into the mechanistic defects caused by specific dynamin mutations considered to underlie a number of diseases.
Genomic saturation mutagenesis and polygenic analysis identify novel yeast genes affecting ethyl acetate production, a non-selectable polygenic trait
March 18, 2016
Isolation of mutants in populations of microorganisms has been a valuable tool in experimental genetics for decades. The main disadvantage, however, is the inability of isolating mutants in non-selectable polygenic traits. Our study shows that genomic saturation mutagenesis combined with complex trait polygenic analysis could be used successfully to identify causative alleles underlying many non-selectable, polygenic traits in small collections of haploid strains with multiple induced mutations.
Differentiated cytoplasmic granule formation in quiescent and non-quiescent cells upon chronological aging
March 3, 2016
Stationary phase cultures represent a complicated cell population comprising at least two different cell types, quiescent (Q) and non-quiescent (NQ) cells. The authors show that the cell fate of NQ cells is largely irreversible even if they are allowed to reenter mitosis. Their results reveal that the formation of different granule structures may represent the early stage of cell type differentiation in yeast stationary phase cultures.
Mitochondrial proteomics of the acetic acid – induced programmed cell death response in a highly tolerant Zygosaccharomyces bailii – derived hybrid strain
January 22, 2016
Very high concentrations of acetic acid at low pH induce programmed cell death (PCD) in both the experimental model Saccharomyces cerevisiae and in Zygosaccharomyces bailii, the latter being considered the most problematic acidic food spoilage yeast due to its remarkable intrinsic resistance to this food preservative. This study offers insights into the mechanisms involved in acetic acid - induced PCD in the Z. bailii-derived hybrid strain ISA1307 by analyzing the yeast mitochondrial protein expression profile of cells challenged by acetic acid.